It is known to provide attic ventilation systems to properly ventilate the attic space often found in buildings. Ventilation of the attic space is desirable to help prevent formation of condensation along the interior surface of the roof, which can damage attic insulation and the building structure itself. Proper ventilation also helps to prevent premature melting of snow accumulated on a building roof. Such premature melting can lead to the formation of ice on the roof. Such ice formations can be both a safety hazard and can lead to roof damage.
Known attic ventilation systems typically comprise a plurality of vents located in the underside, or soffit, of eaves extending from the building roof. Typically, air travels through the soffit vents into the attic space via an opening (herein referred to as the “roof-wall plate opening”) between the underside of the roof deck and the top of the exterior wall of the building (the so-called “wall plate”) and subsequently through an air flow channel formed by a vent baffle disposed adjacent the underside of the roof deck. Ventilation flow typically exits from the air flow channel into the attic space. The attic space may be provided with a separate roof vent to facilitate flow of air from the attic space to the outdoors.
An attic ventilation system directs and controls the ventilation air flow, as otherwise uncontrolled air currents can be sufficiently strong to disturb placement of attic insulation, blowing the insulation about to create areas which are not properly insulated. Uncontrolled air currents circulating in the attic space can also negatively affect performance of the attic insulation by promoting increased convective heat transfer along the top surface of the insulation.
An attic ventilation system also accommodates installation of attic insulation over the entire ceiling, as nearly as possible up to the roof-wall plate opening. To do this, ventilation systems preferably make some provision to block intrusion of insulation into the interior space of the eaves (such intrusion could lead to blockage of the soffit vents) while also providing an air flow channel to permit and control air flow through the soffit vents into the attic space.
U.S. Pat. No. 6,357,185 (Obermeyer) describes a known attic ventilation system and includes a rafter air infiltration block used in conjunction with a conventional roof vent board. The block of Obermeyer is a generally rectangular sheet of material having a plurality of tabs connected to a remainder of the sheet by a plurality of fold lines. The block of Obermeyer serves to prevent intrusion of insulation disposed proximate the roof-wall plate opening into the eave interior space, while the roof vent board provides an air flow channel to allow and control air flow from the soffit vents into the attic space. Installation of a roof ventilation system in accordance with the invention of Obermeyer requires installation of a roof vent board, as well as separate installation of the separate block component. Installation of the block component of Obermeyer requires the installer to fold the block component along multiple fold lines. The installation process is thereby complicated by the need to install two separate components and also by the need to fold the block component along multiple fold lines.
U.S. Pat. No. 6,346,040 (Best) discloses a ventilation panel comprising a rectangular sheet divided by a plurality of fold lines into a rectangular central portion, a pair of side edge portions and an end portion. When the side edge portions and end portions are folded into place, the ventilation panel of Best forms both an airflow channel and a roof-wall plate opening block. In order to install the ventilation panel of Best, it is necessary that the sheet be cut and folded at multiple locations, thus necessitating a relatively complicated and time-consuming installation process.
U.S. Pat. No. 4,581,861 (Eury) discloses a baffle board having side tabs and an end tab, each of the tabs being connected to a remainder of the baffle board by either perforated lines or score lines along which the tabs are bent relative to the remainder of the baffle board. Similar to the ventilation panel of Best, when the baffle board of Eury is folded into an installation configuration, the baffle board forms both an air flow channel and a roof-wall plate opening block. In order to install the baffle board of Eury, it is thus necessary to fold the board along multiple lines. It is further necessary for the installer to exercise judgment regarding the proper positioning of the baffle board (compare FIGS. 4 and 5 of Eury, which illustrate that an installer would be required to judge both the proper spacing of the baffle board from the underside of the roof deck and the proper angle of the baffle board relative to the roof).
There is a need for a vent baffle that is inexpensively manufactured, effectively provides ventilation and insulation baffling, is quickly and easily installed, and that may be installed in a wide range of building configurations. The present invention satisfies this need.